What you write suggests to me that temperatures would, in a worst case scenario, rise beyond approximately +4C after 2100. Often, when I read comments, they seem to imply runaway climate change. Last I checked science was saying that this seems very unlikely to be possible at all, and that a hothouse earth would possibly reach a stable state at approximately +4C.

I also figure that most people to not know that additional warning would require more, and not less CO2. As far as I know, research has shown that humanity would likely not be capable of reaching such a level of emissions.

So, what we are left with is the +4C scenario. Its consequences are uncertain enough, that’s fair. However, when you say that this is an environment humans did not evolve to live in, while technically true, it just makes it sound a lot more dramatic than it probably is likely to be.

To get back to the initial claim about the end of human civilization, this clearly requires unsurvivable conditions globally, including in regions least effected by climate change. While this may sound cynical, the worst effects that are likely to affect Africa, the Sahara, or the Middle East, certainly to not mean the end of human civilization. Implying so is in my opinion dubious. If we look at that Wikipedia article that has been shared, there seems to be a lot of handwaving about a combination of effect supposedly somehow combining to lead to humanity’s extinction mostly by triggering migration and wars. A dubious proposition.

Without trying to go into conspiracy territory, it often seems to me that scientists are hesitant to clearly communicate basic facts around climate change that might be used to oppose needed climate action.

And for the record, I agree that action is needed. However, I disagree with spreading apocalyptic scenarios that seem very unlikely to even be possible, much less a likely outcome. Studies have suggested that climate fears affect a large number of young people, it’s in my opinion a mental health concern. People online love to fuel it, there’s nothing more popular than climate change hyperbole.